1. Field of the Invention
The present invention relates to a bearing assembly, and in particular to improvements in a bearing assembly capable of detecting the number of rotations of a rotatable member made integral with an inner race.
2. Description of the Prior Art
In various industrial machines, there arises the necessity of using a bearing assembly to support a rotatable member and moreover detecting the number of rotations of the rotatable member. An example of it is an anti-skid brake system in a vehicle. This is an apparatus for detecting the number of rotations of wheels and momentarily releasing the brake when the wheels are about to be locked, thereby preventing the locking of the wheels. For the detection of the number of rotations, use is suitably be made of a pulser gear fixed to the rotatable member and an electromagnetic pick-up type sensor fixedly disposed in proximity to the pulser gear.
There has heretofore been a sensor forced into the outer racer of a bearing assembly and having a portion thereof exposed outwardly from the outer race. Accordingly, if a vehicle runs in rainy weather, the sensor is splashed with rainwater and becomes rusty or foreign materials and dust from muddy water and brake pads adhere to the sensor to stain the latter or gravel flies to the sensor and impinges thereon (chipping), and this has adversely affected the result of detection. Yet, if a protective cover or the like is provided to prevent the sensor from being splashed with rainwater, it will correspondingly lead to an increase in number of parts which will also result in complication of the structure. Also, the detecting function may be reduced by the offset between the sensor and the pulser gear.